From owner-freebsd-bugs@FreeBSD.ORG Fri May 9 00:30:08 2003 Return-Path: Delivered-To: freebsd-bugs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 51FA537B404; Fri, 9 May 2003 00:30:08 -0700 (PDT) Received: from mailspool.ops.uunet.co.za (mailspool.ops.uunet.co.za [196.7.0.140]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8296F43F3F; Fri, 9 May 2003 00:30:06 -0700 (PDT) (envelope-from ianf@wcom.com) Received: from copernicus.so.cpt1.za.uu.net ([196.30.72.32]) by mailspool.ops.uunet.co.za with esmtp (Exim 3.36 #1) id 19E2KI-000GWJ-00; Fri, 09 May 2003 09:29:54 +0200 Received: from localhost ([127.0.0.1] helo=wcom.com) by copernicus.so.cpt1.za.uu.net with esmtp (Exim 3.36 #1) id 19E2KH-000EQ8-00; Fri, 09 May 2003 09:29:53 +0200 To: Bruce Evans In-reply-to: Your message of "Fri, 09 May 2003 09:56:39 +1000." <20030509092253.Y61808@gamplex.bde.org> References: <20030509092253.Y61808@gamplex.bde.org> From: "Ian Freislich" X-image-url: http://www.digs.iafrica.com/gallery/ian-small.gif X-BOFH: true X-LART: Depleted uranium X-No-Junk-Mail: I do not want to get *any* junk mail. You have been deleted Date: Fri, 09 May 2003 09:29:53 +0200 Message-ID: <55435.1052465393@wcom.com> Sender: ianf@wcom.com cc: freebsd-bugs@freebsd.org cc: FreeBSD-gnats-submit@freebsd.org Subject: Re: kern/51982: sio1: interrupt-level buffer overflows X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 May 2003 07:30:08 -0000 Bruce Evans wrote: > On Mon, 5 May 2003, Ian Freislich wrote: > > > >Description: > > Transferring data at "high" speed 115200bps over the serial > > line (even though the actual incoming line stream is about > > 37000bps according to the modem LCD panel) results in the > > following messages on the console at a rate of about 1 log > > line every 10 to 15 seconds. > > > > These buffer overruns have gradually become more frequent > > from about 3 lines and 24 overruns a day around September > > 2002 (when I started running Current - 4.x does not suffer > > from this) to the current flurry. > > -current has excessive interrupt latency caused by Giant locking almost > everything. > > Try changing this line in sio.c: > > cp4ticks = speed / 10 / hz * 4; > > to something like: > > cp4ticks = speed / 10 / hz * 40; Thanks. Making this change seems to have fixed the problem. Will this be committed or do I need to maintain this privately until the larger interrupt latency problem is fixed? > Transient interrupt latency problems are supposed to be made harmless > by using rts flow control. There is a PR (maybe from you?) about rts > flow control apparently not working for one modem. Not me. Ian